Sustainable sourcing

I’ve received the first seed catalog of the season! It’s time to start ordering seeds and planning plant purchases for next spring. I want to be realistic and environmentally sound. That poses some new challenges this year.

Previous years' seeds were stored in the refrigerator

    I love spending cold winter evenings mooning over catalog portraits of perfect vegetables and lush, bright flowers. A seed packet doesn’t cost much, and I convince myself that I’ll find space for that special squash vine or those five varieties of string beans. I also tend to over-estimate how many sunny spots there are for annual flowers in the insectary bed or the perennial borders.

Everything looks perfect in the catalog

    The miracle of seeds germinating and sending up their first leaves never gets old for me. I like sowing seeds and coddling seedlings through their first weeks under lights. I don’t do so well with the next stage, growing those seedlings into sturdy young plants bursting with energy for their move to the garden. When I compare my willowy seedlings to their hearty counterparts at the garden center, I often resolve to stop sowing seeds at home and depend on the experts.

My zinnia seedlings look puny compared to the garden center's

    This year things look more complicated for two reasons. First, I’m still trying to avoid introducing neonicotinoid insecticides into my yard. Even seeds may be treated with these pesticides, which are toxic to bees and other beneficial insects and persist for years in soil and plant tissues. I don’t want them here because I’m trying to foster native insects, not kill them. In addition to shopping for neonic-free plants, no easy task, I also aim to buy seeds that aren’t treated with pesticides.

Neonics poison bees when they visit flowers

    That’s why I prioritize organically-produced seeds, sure to be pesticide-free. It’s convenient that the year’s first seed catalog comes from The Natural Gardening Company, the oldest certified organic nursery in the country. This seed house emphasizes vegetables over flowers, and being in California, they don’t necessarily feature varieties suited for the Northeast.     

     Closer to home, there’s Johnny’s Selected Seeds in Maine, which offers lots of organic seeds. Even if they're not organic, Johnny’s seeds are untreated, and none contain neonicotinoids. Even Burpee offers some organic seeds. It’s hard to pass up beautiful new varieties in the catalogs that aren’t organic, but I have enough organic choices to make
it bearable.

Basil and borage growing from neonic-free organic seeds

    Second, I’ve made it a goal to buy less plastic with my garden purchases. That means trying to bring home fewer plastic six-packs and individual plastic pots of seedlings. For the last couple of years, my friend Jennifer and I have bought some of our herbs in fiber pots. These are theoretically compostable. At my house, they turn into dog chews before they can decompose. At least they’re plastic-free.

    What about the rest of my plant purchases? Almost all at local garden centers will be offered in plastic pots. 

Organically-grown seedlings, but they're in plastic pots

I’m going to look into bareroot options. Strawberry plants are often shipped this way without soil or containers, and I’ve read that other plants can be too. Let’s share sources!

                         Happy Holidays

Sex, drugs, and plant propagation

Which is better, sexual or asexual reproduction? It depends who’s doing the reproducing. This spring I’m making new plants both ways. Seeds are produced through sexual reproduction. Each seed has two parents with different genetic make-ups. That means each seed, and the plant it grows into, is a unique individual, like us. I’m growing a lot of my new plants from seed, including vegetables, herbs, and annual flowers.

Each borage and basil seedling is a genetically unique

    Asexual reproduction accounts for a lot of the perennials, trees and shrubs we buy. If you’re a breeder who wants to make sure your dogwood or azalea is exactly like its parent, you clone it. Unlike human tissues (so far), plant tissues have the ability to reproduce whole plants from parts of the parent plant.

A desirable rhododendron can be cloned infinitely

     Right now I’m growing cuttings from last year’s rosemary, bearberry (Arctostaphylos uva-ursi), and coleus. I’m hoping to do the same with tarragon and oregano I bought at the garden center. If these cuttings take root and grow, the plants they grow into will be genetically identical to the parent plant.

Cuttings from bearberry and coleus are clones

I’ve read that some named shrub varieties consist entirely of clones from one desirable plant. Many plants, but identical genes.

    People concerned about biodiversity have a problem with this system. In addition to encouraging us to grow native plants, they want us to foster genetic diversity among plant species. The reason is that a broader gene pool allows a species to adapt to changing environmental conditions. Some individuals in the population will develop greater resistance to heat, drought, flooding, and other challenges. As climate change speeds up changes plants face, they need to be ready to evolve in response.

    There’s an inherent tension between promoting biodiversity and maintaining desirable varieties. If you’re trying to grow a particular tomato, say ‘Brandywine,’ which is open pollinated (not a hybrid), you don’t want your ‘Brandywine’ plants fertilized by pollen from other tomato varieties. 

Tomato growers want to keep varieties distinct

     But if you’re just growing a patch of perennials, say native purple coneflowers (Echinacea purpurea), there’s no reason not to let them mix with nearby members of their species and create a genetically mixed population. In fact, your stand of coneflowers will be more likely to survive if it includes members with different genes that can tolerate varying conditions.

A genetically diverse coneflower population is adaptable

    Except for letting willing self-seeders do their thing, I haven’t propagated perennials from seed. When I want more, I may divide the plants or, as with rosemary, bearberry, and ivy, grow more from cuttings. If a snippet from the growing end of a plant is willing to send down roots, why not make more that way? Divisions and cuttings make clones, just as tissue cultures made by breeders from a few cells grow into clones of a newly-developed perennial. In future I want to learn to grow native perennials from seed so I can help maintain their genetic diversity.

Felix, a new garden helper visiting from New York

I’m off on a trip to the Southeast, hoping to experience spring flowers there and again at home when I return. See you in two weeks.

Sowing diversity

It’s seed-starting season, and I’m about to start my second round of annual and vegetable seeds. 

Time to plant some more seeds

With this in mind, I was eager to hear a talk this week by Randi V.W. Eckel, an entomologist and founder of Toadshade Wildflower Farm in New Jersey. She made the case for starting native perennials from seed and then offered some pointers on how to do it.

    Entomologists advocate growing native plants in our backyards, because native insects are adapted to live off them. 

Native plants feed native insects

Randi also pointed out that seed-grown plants are genetically diverse, whereas perennial plants that are multiplied by division, cuttings, or tissue culture are clones—genetically identical copies of the parent plant. In diversity, there is strength.

    My experience with seeds comes from common vegetables and flowers bought from large mail order seed houses. I was surprised to learn how different it could be to work with seeds of native perennials. Think they’ll all sprout around the same time? Think again—it’s adaptive for them to spread out their germination times so that one disaster won’t wipe them all out. It turns out that predictably timed germination is one of the characteristics our tame seeds have been bred for.

    Randi listed at least nine special requirements that seeds may have for germination, all adaptations that improve their chance of growing into successful populations in the wild. Some require periods of moist cold conditions, some dry cold, some alternating periods of warmth and cold. Some need their seed coat “scarified,” which can be done by scratching the seeds with sand paper (I wholeheartedly agree with Randi’s point that oft-repeated advice to do this with a razor blade is a recipe for losing a finger).

Seeds of blue false indigo (Baptisia australis) need scarification to germinate

     I think I know now why I’ve never been able to grow common milkweed (Asclepias syriaca), although I’ve brought home seeds with their silky parachutes several times when the pods opened in fall.  

Seeds of common milkweed are equipped to travel

Although this plant is usually regarded as a weed, I like the idea of its attracting migrating monarch butterflies. Monarchs lay their eggs on milkweed because it’s what their larvae need to eat. I pictured a gleaming orange and black monarch emerging from its chrysalis in my yard. Wouldn’t that be cool!

Monarchs are milkweed specialists

      Right now I’ve got a flat of unfortunate milkweed seeds mostly failing to sprout under lights in my kitchen, this time from a packet I was given by a friendly seed collector last spring. Randi pointed out that milkweed seeds need light to germinate. I shouldn’t have been covering them with soil outdoors or growing medium indoors. 

Luckily these milkweed seeds got enough light to sprout. I planted the rest too deep.

    So when I start this week’s seeds, I’ll try sowing milkweed seeds on top of the growing medium. But Randi’s talk convinced me to keep buying most of my native perennials from nurseries like hers. Let the experts provide the care the seeds and young plants need. If my native perennials succeed in multiplying in the garden, so much the better.

Almost spring

Is it late winter or early spring? The calendar date is still far from the vernal equinox, but on the glass-half-full side, the garden is already starting to wake up. Snowdrops have been blooming since early February. 

 
Our first flowering tree is in bloom, a witch hazel, Hamamelis ‘Arnold Promise.’ 

I’m declaring the start of the gardening season—whoopee!

    It’s time—or past time—to order seeds to plant this spring. I’m feeling a new appreciation for seeds. In doing the research for my book, I learned to my surprise that producing plants for garden centers is far from a local enterprise. I had imagined just one step between a grower and the garden center where I shop. The reality turned out to be much more complicated. I had to come to terms with the fact that plants I bought came with a significant carbon cost.

    Perennials come from multiple starting points, depending on the plant. Jan Lesnikoski, a grower at Sunny Border in Connecticut, explained to me that wholesale nurseries buy seeds and plants from around the world. Sunny Border uses tissue culture products imported from South Africa, Holland, Turkey, and Poland (tissue culture converts tiny pieces of plant tissue into large numbers of genetically identical plantlets). Large plantations in Costa Rica and Ecuador with space to maintain supplies of stock plants send unrooted cuttings for Sunny Border to root and grow to saleable size.

     Garden centers like the one I favor, Russell’s in Wayland, Massachusetts, do grow annuals and vegetables on site, either from seeds or from plugs (small young seedlings) they buy from regional wholesale brokers. 

    This new knowledge about global sourcing makes starting plants from seeds seem more desirable. Although seeds may come from all over the world, they’re small and packaged by nature for easy travel, so shipping them incurs less environmental cost.

    This year I’m planning to buy my usual vegetable and annual flower seeds: arugula, lettuce, peas, beans, cucumbers, nasturtium, sunflowers and zinnias. Most I’ll plant directly in the garden; a few I’ll start indoors under lights. 

    Renewing my membership in the Massachusetts Horticultural Society yielded a gift certificate from White Flower Farm. Despite wanting to be more sparing about buying perennials, I think I’ll use the gift to buy some that are popular with beneficial insects I’d like to attract.

    I have my eye on a selection of coastal plain Joe Pye weed that's native to the eastern US. 

Eupatorium dubium 'Baby Joe'

It stays 3 to 4 feet tall, smaller than Eupatorium maculatum, the species I’m used to seeing. I also want a butterfly weed

Butterfly weed, Asclepias tuberosa

to complement the swamp milkweed, Asclepias incarnata, that I grew last year.

    My ambition is to learn more about growing native perennials and shrubs from seed. That way I can expand my supply of plants without incurring the carbon cost of shipping them from around the country or around the world.